Node.js 26 LTS: Config Files, Sync ESM require, Built-in Throttle/Debounce

Node.js Version Lifecycle Positions

As of October 28, Node.js 26 enters Active LTS, becoming the primary version for the next year where new features are added. Node.js 24 moves from Active LTS to maintenance mode, receiving only bug and security fixes with features frozen. Node.js 22 is in the final stage of maintenance; after its end-of-life (EOL), no further patches, including security patches, will be provided. The key point: end of maintenance does not mean the version cannot be used, but that vulnerabilities will no longer be patched.

Three Reasons to Upgrade to Node.js 26

1. Configuration File Support

Previously, CLI flags such as --enable-source-maps and --max-old-space-size=4096 had to be placed in package.json scripts or shell scripts, making them difficult to review and manage across environments. Starting with Node.js 26.12, these flags can be moved into a dedicated configuration file, enabling version control, environment-specific overrides, and code review.

{
  "enable-source-maps": true,
  "max-old-space-size": 4096
}

Moving parameters into a file allows them to be version-controlled, overridden per environment, and reviewed. The problem with command-line arguments was never that they were hard to write, but that they could not be reviewed.

2. Synchronous require() Loading of Most ESM Modules

Node.js 26 allows require() to synchronously load most ECMAScript modules (ESM). Previously, pure ESM packages used in CommonJS (CJS) projects required dynamic import(), forcing synchronous initialization logic to be rewritten as asynchronous. Now, in most scenarios, require() works directly. The article notes the limitation: modules with top-level await still cannot be loaded synchronously due to language-level constraints.

3. Built-in util.throttle and util.debounce

Node.js 26 adds util.throttle and util.debounce to the standard library, eliminating the need for third-party packages like lodash.throttle. This continues a trend where Node's standard library absorbs commonly used utilities (previously fetch, structuredClone, AbortSignal.timeout), reducing dependencies and supply-chain risk.

// Before: npm i lodash.throttle
import throttle from 'lodash.throttle'

// Now
import { throttle } from 'node:util'

Upgrade Guidance

Upgrading across one major version is typical; skipping two versions is also common because Node.js releases a major version every two years. Many teams already upgrade every other LTS. For teams that have not upgraded to Node.js 24, the article recommends upgrading directly to Node.js 26 in one step, while reviewing the configuration file changes and ESM loading behavior changes together.